APPLICATION OF THE SECANT METHOD TO PREDICTION OF FLOW CURVES IN MULTI-MICROSTRUCTURE STEELS

The elastoplastic flow curves of a dual microstructure, i.e. ferrite-p earlite or ferrite-bainite steels or tri-microstructure, i.e. ferrite- bainite-martensite steels have been calculated using the secant method proposed by Weng. The flow curves of the constituents were given by t he Swift equation in which the material constants were described as fu nctions of microstructural factors, chemical compositions and process parameters. The iterative calculating procedure to predict a stress-st rain curve of a multi-microstructure steel has been introduced. The ca lculated flow curves show good agreements with experimental results. ( C) 1997 Acta Metallurgica Inc.